Sound amplifier



Sept. 13, 1923.

M. NYSTROM 'SOUND AMPLIFIER Filed Nov. 191

I 1? 1' i H 1m WW Inventor Mlrm Patented Sept. 18, 1923.

UNITED STATES 1,466,166 PATENT OFFICE.

MARTIN NYSTROM, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE BItUNSWICK-BALKE- COLLENDER COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

SOUND AMPLIFIER.

Application filed November 6, 1916. Serial No. 129,715.

To all whom it may concern: I

Be it known that I, MARTIN NYs'rnoM,

a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Sound Amplifiers, of

which the following is a specification.

This invention relates to talking machines and has for its-primary object the provision of an amplifier of. Wood constructed to insure its maximum efficiency as a conductor and distributor of sound under varying atmospheric conditions.

A further object of my invention is the provision of a wood amplifier for talking machines in which the customary joint between the mouth neck portion and the portion of the amplifier leading to the tone arm is eliminated. g

Further objects and advantages of my 1nvention will be apparent as itis better understood by reference to the following specification when read in connection with the accompanying drawing, illustrating the pre ferred embodiment thereof, in wh1ch- Fig. 1 is a plan view partially in section of an amplifier according to my invention with the damper applied thereto;

Fig. 2 is a section on the line 2--2 of Fig. 1;

Fig. 3 is a detail in section of the damper, and

Fig. 4 is a detail in elevation, illustratmg the construct-ion of the amplifier.

Referring to the drawing, 1 indicates the side walls of the amplifier which are continuous from the mouth portion to the end of the upwardly extending neck portion leading to the tone arm (not shown) and are-bent in the manner illustrated in the drawing to provide for the increasing amplitude of the sound vibrations as they emerge from the amplifier. The side walls 1 are constructed of an outer sheet 2 of wood of substantial thickness and two layers 3 of wood veneer firmly secured by suitable adhesive to the sheet The side walls 1 are grooved at 4: to receive the edges of the top and bottom walls each of which consists of two layers 5 of veneer firmly secured together by suitable adhesive. The

top and bottom walls are bent indicated in Fig. 2. A plurality of glue cleats 6 are secured to the inner, faces of the side walls 1 exteriorl'y of the amplifier to provide additional support for the top and bottom walls. At the mouth of the amplifier strips 7 extend across and are secured to the top and bottom Walls of the amplifier.

In the upwardly extending portion of the amplifier I provide a damper consisting of a layer 8 of felt or other suitable material firmly clamped between plates 9 and 10, preferably of metal and secured together by rivets 11. The layer 8 extends beyond the edges of the plates 9 and 10. The plate 10 is bent at 12 providing a square socket to receive the operating rod 13 which extends through the side wall 14 of the cabinet in which the amplifier is mounted and is provided with an operating knob 15. A plate 16 is secured to the side wall 14 about the opening through which the rod 13 extends. The rod 13 is journaled in suitable openings in the side walls 1 of the amplifier and a stop 17 is provided within the sound passage to limit downward movement of the damper. By rotating the rod 13 the damper may be moved between the positions indicated in full and dotted lines in Fig. 2 of the drawing and may be brought to rest in any desirable position to control the volume of sound which is permitted to pass to the amplifier.

The foregoing structure provides a sound amplifier which has many desirable features, the most prominent of which is the continu ity of the walls throughout the length or the amplifier. This is contrar to the usual construction of wood ampli ers and provides a smoother sound passage and eliminates extraneous vibration with a resulting improvement in the quality of the sounds which are delivered from the amplifier. The dam or is of simple construction and is readily controllable to vary the volume of sound at the will of the operator.

It will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the inventlon or sacrificing any of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A sound amplifier for talking machines embodying a bell portion and a neck portion, the latter curving laterally and disposed approximately at a right angle to the bell por tion, of the walls of the amplifier consisting of fiat sheet, the side walls having grooves near their longitudinal edges in which the edges of the top and bottom walls are received, and cleats adhesively secured to the outer faces of. the top and bottom walls and to the inner faces of the projecting marginal portions of the side walls.

2. A sound amplifier for talking machines embodying a bell portion and a neck portion, the latter curving laterally and disposed a proximately at a right angle to the bell portion, each of the walls of the amplifier consisting of a fiat sheet, embodying adhesively secured wood veneers, opposite sheets having grooves to receive the edges of the intermediate sheets, and cleats adhesively secured to the projecting marginal portions 01 the grooved walls and to the ad acent edge portions of the walls seated in the grooves.

3. A sound amplifier for talking machines embodyin a hell portion and a neck portion, the Latter curving laterally and disposed approximately at a right angle to the bell portion, each of the walls of the amplL fier consisting of a fiat sheet, the side walls being grooved near their longitudinal edges and embodying relatively thick outer sheets of wood and relatively thin inner plies of wood adhesively secured, and the top and bottom walls comprising relatively thin plies of wood having their edges secured in the grooves of the side walls, and cleats adhesively secured to the projecting marginal portions of the side walls and to the edge portions of the top and bottom walls.

MARTIN NYSTROM.

Witnesses CHAS. H. CALFEE, STEPHEN RUBUY. 

